The archaeological site itself is located above the beach, on a coastal terrace, that was formed by sediments of allochthonous (exotic) and autochthonous (local) origin.
[1] After examining several artifacts found on the coast of the Valdivia and Concepción areas, archaeologist Menghin claimed the findings belong to a "Chanchaense Complex" or culture extending from Quiriquina Island (37° S) in the north to Tierra del Fuego (55° S) in the south.
The inhabitants of Chan-Chan had access to a substantial diversity of rocks, with schists, basalt, quartz and chert being found close to or at the archaeological site.
[1][2] As of 2005, 3484 stone handcrafts and 12,050 carve outs have been found in Chan-Chan as well as bones from mammals, birds and fishes apart from middens[3] of marine invertebrate shells.
The same kind of disc-shaped cobbles are found in the lower layers of human occupation in Chan-Chan, as well, leaving open the possibility that they were deposited by an ancient tsunami, according to Pino and Navarro.